Electrically conducting polymers and other electronically functionalised materials are key components for the development of polymer electronics. However, the realisation of novel polymer electronic components is dependent on technology for realisation and assembling of patterns of such materials on a large number of different substrates. Patterns of electrically conducting polymers can be achieved in different ways. Either the electrically conducting polymer is deposited in a defined pattern on the substrate, or a sheet, layer or film of electrically conducting polymer is deposited, which is subsequently patterned using subtractive techniques or local deactivation. In the case of electrically conducting polymers, such deactivation may be achieved through a substantial decrease in, or complete elimination of, conductivity in the material. Thus, for example, a film of an electrically conducting polymer material may be patterned through rendering certain parts, sections, segments, lines etc non-conducting.
Known methods of achieving desired deactivation of polymer materials on substrates include exposing the materials to strongly oxidising, wet chemical agents, such as aqueous solutions of sodium hypochlorite or potassium permanganate. These solutions can be applied locally using printing techniques like ink-jet, screen, offset, flexographic etc. Known methods like these are described e g by Agfa-Gaevert N.V., Specialty Foils and Components, in product documentation relating to patterning of Orgacon™ films using Strupas ink (available on the world wide web at the time of filing on http://sfc.agfa.com/pdf/PatterningStrupas.pdf). However, such known methods suffer from a number of drawbacks, which limit their applicability and usefulness. The solutions used are highly oxidising, and therefore strongly corrosive to any equipment involved. In addition, chlorine containing reagents are harmful to the environment. Furthermore, the fact that the wet chemical reagents diffuse laterally through the material that is to be patterned results in a poor maximum resolution of the pattern.
An alternative method in the prior art for patterning polymers is the use of photolithography in combination with photoresist overlayers for realising of patterns with high resolution (i e on the micrometer scale) by exposing of the polymer to an oxygen and fluorine containing plasma. Known methods like these are described in e g Lowe J, Bartels C, Holdcroft S, Canadian Journal of Chemistry, vol 76(1998), 1524-9; Jager EWH, Smela E, Inganas O, Science, vol 290(2000), 1540-5; Chinn D, Janata J, Thin Solid Films, vol 252(1994), 145-51. These methods, too, have disadvantages, considering that plasma processes require vacuum equipment, and that the use of photoresists requires the manufacture of new photolithography masks whenever the desired pattern is modified.
Thus, there is a demand in the art for methods for the patterning of polymer materials that improve the art and do not suffer the disadvantages of known methods.